摘要
（Ba0.5Sr0.5）1-xPrxCo0.8Fe0.2O3-δ（BSPCFx;x=0.00-0.30） oxides were synthesized by a sol-gel thermolysis process using combination of PVA and urea,and were also investigated as cathode material for intermediate temperature solid oxide fuel cells（IT-SOFCs）.X-ray diffraction（XRD） results showed that all the samples formed a single phase cubic pervoskite-type structure after being calcined at 950 oC for 5 h and the lattice constant decreased with the Pr content increasing.The electrical conductivity of Ba0.5Sr0.5Co0.8Fe0.2O3-δ（BSCF） was greatly enhanced by Pr-doping.The thermal expansion coefficient（TEC） of BSPCFx was increased with the content of Pr increasing,and all the thermal expansion curves had an inflection at about 250-400 oC due to the thermal-induced lattice oxygen loss and the reaction of Co and Fe ion.Ac impedance analysis indicated that BSPCFx possessed better electrochemical performance.The polarization resistance of the sample with x=0.2 was only ～0.948 Ω cm2 at 500 oC,significantly lower than that of BSCF（～2.488 Ω cm2）.
（Ba0.5Sr0.5）1-xPrxCo0.8Fe0.2O3-δ（BSPCFx;x=0.00-0.30） oxides were synthesized by a sol-gel thermolysis process using combination of PVA and urea,and were also investigated as cathode material for intermediate temperature solid oxide fuel cells（IT-SOFCs）.X-ray diffraction（XRD） results showed that all the samples formed a single phase cubic pervoskite-type structure after being calcined at 950 oC for 5 h and the lattice constant decreased with the Pr content increasing.The electrical conductivity of Ba0.5Sr0.5Co0.8Fe0.2O3-δ（BSCF） was greatly enhanced by Pr-doping.The thermal expansion coefficient（TEC） of BSPCFx was increased with the content of Pr increasing,and all the thermal expansion curves had an inflection at about 250-400 oC due to the thermal-induced lattice oxygen loss and the reaction of Co and Fe ion.Ac impedance analysis indicated that BSPCFx possessed better electrochemical performance.The polarization resistance of the sample with x=0.2 was only ～0.948 Ω cm2 at 500 oC,significantly lower than that of BSCF（～2.488 Ω cm2）.
基金
Project supported by Key Natrual Science Foundation of Education Department of Inner Mongolia(NJZZ11013)
China Postdoctoral Science Foundation,and Higher-level Talents of Inner Mongolia University (Z20090105)
